The Clem Jones Tunnel (CLEM7) provides a critical river crossing that bypasses the CBD to link Brisbane’s growing northern and southern suburbs, with direct connections at Bowen Hills, Kangaroo Point and Woolloongabba.
The 6.8 kilometre tunnel provides an alternative route to the heavily used Story Bridge, and additional access to the Brisbane Airport, Chermside Shopping Centre, Royal Brisbane Hospital and the RNA Exhibition grounds, all north of the river, and the Brisbane Cricket Ground, Princess Alexandra and Mater Hospitals and the Pacific Motorway to the Gold Coast, south of the river.
The Clem Jones Tunnel was constructed using recycled materials
The design and construction of the project was contracted to LBB JV, a joint venture between Leighton Contractors (now CPB Contractors), Baulderstone (now Leandlease) and Bilfinger Berger who worked with Alex Fraser to ensure recycled concrete roadbase was developed specifically to meet engineer specifications.
A significant challenge was transporting stabilised material up to eight kilometres into the tunnel before it was laid and then subjecting it to heavy traffic during construction.
Engineers and project managers were pleased with how efficiently the material was laid and compacted. The material performed well and passed all geotechnical tests.
Environmental and cost savings
Recycled roadbase is approximately 15-20 per cent lighter compared to materials produced from Queensland quarried rock, which means less material is required.
On the CLEM7 project the benefits of using recycled materials was a cost saving of an estimated $570,000, and 725 less truck movements.
The use of recycled materials also prevented the extraction of 120,000 tonnes of natural resources, saved more than 100,000 tonnes of waste from going to landfill and reduced carbon emissions by around 1,000 tonnes.